Worm gears are often used when large rate reductions are needed. The decrease ratio is determined by the number of starts of the worm and amount of tooth on the worm equipment. But worm gears possess sliding contact which is calm but will produce heat and have relatively low transmission effectiveness.
For the materials for production, in general, worm is made of hard metal as the worm gear is made from relatively soft metal such as for example aluminum bronze. This is since the number of tooth on the worm gear is relatively high in comparison to worm with its number of begins being generally 1 to 4, by reducing the worm equipment hardness, the friction on the worm the teeth is reduced. Another characteristic of worm manufacturing may be the need of specialized machine for gear reducing and tooth grinding of worms. The worm equipment, on the other hand, may be made with the hobbing machine worm wheel china utilized for spur gears. But because of the various tooth shape, it is not possible to cut a number of gears at once by stacking the gear blanks as can be done with spur gears.
The applications for worm gears include equipment boxes, fishing pole reels, guitar string tuning pegs, and where a delicate rate adjustment by utilizing a large speed reduction is necessary. When you can rotate the worm equipment by worm, it is normally not possible to rotate worm by using the worm gear. That is called the personal locking feature. The self locking feature cannot always be assured and another method is preferred for accurate positive reverse prevention.